Method of making reinforced balls



15 1950 F. T. ROBERTS 2,519,059

METHOD OF MAKING REINFORCED BALLS Filed June 18, 19.46 3 Sheets-Sheet l Aug. 15, 1950 F. T. ROBERTS 5 5 METHOD OF MAKING REINFORCED-BALLS Filed June 1a, 1946 s Sheets-Sheet 2 VEQI Aug. 15, 1950 F. T. ROBERTS 2,519,069

I ms'moo OF MAKING REINFORCED BALLS Filed June 18, 1946 s SheetS -Sheet s Pleas: Aug. 15, 1950 2,519,069 METHOD or MAKING REINFORCED BALLS Fred Thomas Roberts, Bidgefield, Conn. Application June 18, 1946, Serial No. 677,640 13 Claims. (01. 154-16) This invention relates to a wrapped playing ball for use in various games, such as soccer,

basketball, etc. This ball has an impervious center member'to contain fluid under pressure injected through a valve, 9. wrapping to .provide strength for the ball, and an outside covering of wear-resisting material.

The present invention is concerned with the method of making the ball, which employs the steps of forming a-foundation unit as separate sections of vulcanizable material (for instance two hemispheres of raw rubber) each reinforced by a winding of vulcanizable material; thereafter joining such sections by the use of interposed vuicanizable material between the coacting edges of the sections, and thereafter applying one or more supplemental reinforcin windings of stretchable rubberized tape, fabric, or cord. After the final winding has been applied, the reinforced ball'is encased in a cover of rubber or leather.

I prefer to employ bias tape or perforated tape for the windings, as such tape has only short threads lying in a sort of floating state, being held together by the rubber surrounding such threads, and is accordingly quite stretchable and will also lie evenly on the ball; The stretchability provided by such winding allows the wall of the ball to yield, in case of a concentrated blow, without putting a strain on the winding. and results in a stronger wall and one less liable to rupture.

My method may be carried out in two manners. In the first manner of operation, I form the foundation unit as a complete closed body or sphere about an interior core and then cut the unit into sections, and remove the core and thereafter join the sections by vulcanization by the insertion of a separate strip between abutting edges of the sections. In the second manner of operation, I form the foundation unit originally as separate sections, each providing a vulcanizable body portion and I'reinforce these with external windings. Each body portion made in this second manner has a projecting annular flange comparable to the brim of a hat. After removing the reinforced sections from their molds, I join them together -by abutting the flanges, which provide the necessary material for an effective, seam at the junction.

In each manner of operation, I prefer to seat the individual section by means of a vacuum applied between it and the wall against which it seats. In the first manner, such wall may for instance be a concave hemisphereseating the rubber which thereafter embraces an interior spherical mold. while in the second manner the seating may be against a convex hemisphere with an outward equatorial extension, which itself forms the mold and makes the hemispherical section with the brim.

In each manner of operation, following the joining of the sections of the foundation unit, a reinforced fabric winding is applied and thereafter a suitable cover preferably attached. If

the cover is to be rubber, vulcanization of the unit may wait until the cover is in place and be effected as the final operation. If a leather cover is to be applied, vulcanization should take place prior to the applying of the final cover.

Figs. 1 to 6 of the drawings illustrate the successive steps employed in the first manner of forming the foundation unit; Figs. 8 to 13, the successive steps in the second manner, while Fig. 7 illustrates a supplemental wrapping which may be employed with either manner of operation.

In the drawings, Fig. 1 is a diametric section of a two-part cavitary mold in which rubber has been seated, this view showing also a. molding sphere mounted in one of the lined hemispheres and a rubber valve seated on the exterior of the molding sphere; Fig. 2 illustrates the manner of wrapping of one layer of reinforcing tape on the rubber sphere enclosing the molding sphere, as produced by the apparatus of Fig. 1; Fig. 3 is a similar view illustrating the application of. a second layer of reinforcing tape; Fig. 4 is a view. of a two-part mold in separated condition, illustrating the application of a rubber cover to the reinforced foundation A unit with the molding sphere within it, which view shows the unit in the act of being placed; Fig. 5 is a view of a foundation unit after it has been removed from the mold shown in Fig. 4 and severed to form two hemispheres, and the molding sphere removed, the view indicating also an interposed ring of rubber for the seam; Fig. 6 is a view of a mold with the two hemispheres of Fig. 5 seated therein and rubber rings applied across the diametric edges of the seated hemispheres; Fig. '7 is a view illustrating a reinforcing wrapping of rubberized tape which, if desired, may be applied to the exterior of one or more of the layers in forming the wall of the complete ball; Fig. 8 is a view of an'appaon the exterior of a portion of the hemisphere; Fig. llisaviewofatwo-partmoldinwhich two of the reinforced sections, as produced by Fig. 10, are positioned ready to be brought into conjunction when one part of the mold is swung over on top of the other; Fig. 12 is a sectional detail of the Junction of the two brims when the mold members of Fig. 11 are brought together;

Fig. 13 is a view of a reinforced ball as produced A by the apparatus resulting from the use of Fig. 11 after the surplus material of the brims has been removed.

In Fig. .1. lo and n indicate two mold members surrounding grooves, causes a sheet of rubber placed across the cavity and groove to be seated therein, thus clamping the margin of the sheet and producing a hemisphere 20 ofrubber with an annular flange ii in the annular groove and I with an annular ridge 22 at the junction of the hemispherical body and flange.

- the rubber is seated in the two cavitary molds, as shown in Fig. 1, I place in one of the lined cavities a forming member which is shown as a hollow sphere of metal or convenient material. This molding sphere is of such size that it may press the rubber member 20 tightly against the wall of the cavity. An opening through the wall of the forming member and a surroundingrecess in the exterior of the wall enables a rubber valve 15 with an annular thin skirt as to be located on the exterior of the forming member, as shown in Fig. 1.

The mold member I l with its seated rubber hemisphere is adapted to be mounted on top of t v the sphere 80, shown asseated in the mold member II). when this is effected and the mold members pressed together, the two rubber sections are joined in the equatorial seam formed by the seated rubber and at the same time the cutting edges l2 pinch of! the surplus rubber, while the valve to which cement has been applied adheres to the interior of the rubber sphere.

It is convenient to connect the mold member pulley u by which it may be rotated. spindlefl isslidablymountedinitsstandard and embraced by a coil spring 48 which presses its cup ll against the ball. The ball is indicated at A mounted between the cups.

When power is applied to the pulley of Fig. 2, the ball A is rotated about a horizontal axis and during this rotation I feed onto it a strip of rub-, berized tape with the edges successively overlapping and thus form the general tape layer designated 13 extending from one cup 43 to the other cup 44.

I now release the partially wound ball from the apparatus by drawing back the cup I and give the ball a quarter turn to cause the. layer B to extend in zones between the two cups. 1 then apply power again to-the apparatus, rotate the partially wound ball and apply a section strip of rubberized tape over the wound ball in overlapping edge relation to provide the layer C, as shown in Fig; 3, thus causing the ball to be completely covered by these two spiral windings of tape, which may be applied either with or without such winding as shown in Fig. 7.

Indeed, a winding like Fig. ,7 may be placed on the innermost layer of the ball, as above alluded to, or may be placed between thefirst and second a spiral windings or after the third winding, or in l l with the mold member 10 by a loose hinge connection so that both mold members may readily face upwardly on the same table or support, and, after the rubber hasbeen seated, the member ll may be readily swung over on top of the member i The hinge connection is efiected by providthe mold member in with an upright loop l8 and the mold memberjil with an ear having a cross pin is loosely occupying the loop.

After the hollow sphere of rubber has been formed about the forming sphere 30 the suction 'is released and the mold members separated and the hollow rubber ball with the surrounded forming sphere is removed. I may now place this removed article directly in the apparatus of Fig. 2, or I may give it a preliminary reinforcing wrapping of rubberized tape (as indicated at F in Fig. 7') and then place it in that apparatus.

. The apparatus of Figs. 2 and 3 comprises a pair of standards ill in which are mounted two spindies ll and 42 respectively, each having at'its inner end a dish or cup 43, 44 adapted to engage the ball. 4| is provided with a some cases may be usedas a substitute for one or both layers B and C. On the other hand, a good ball may be produced by omitting the winding on Fig. 7 altogether and relying for reinforcing on the crossing spiral windings of Figs. 2 and 3.

Following the application of the multiple windings of crossing reinforced tape on the rubber ball, this ball with the forming sphere still within it is transferred to hemispherically seated rubber in mold cavities, as shown for instance in Fig. 4. 'lhe apparatus there shown comprises a pair of mold members and I, each provided with a hemispherical cavity surrounded by an annular groove, the grooves being connected with suction nipples 63 in the same manner as described in reference to Fig. 1.. The mold membersofFig.4arequitesimilartothoseofFig. l but the hemispherical cavities are somewhat larger by the amount of the thickness of the reinforcing winding. The annular cutting edges are also slightly different, in that in one region the cutting edge is omitted for a short distance and in that region the ridge is transversely grooved to allow a suction pipe 65 to be seated therein.

Sheets of rubber are placed across the mold members 60 and GI and seated therein to form the hemispherical layers 10 with surrounding flanges II and intermediate nearly annular ridges 12. After such rubber has been seated by suction, I place in one of the cavities the wound ball as delivered by the apparatus of Fig. 3, or with an additional or substitute reinforced winding, if desired, the exterior being covered with cement. Fig. 4 shows at 30 the forming sphere; at A the first rubber layer which is to form the interior lining of the ball and at B, C the conventional illustration of the surmounting windings of rubberized tape.

After the mold members of Fig. 4 have been brought together on the reinforced article shown in that figure, suction is applied to the pipe 65 which exhausts air from the space between the reinforcing winding and the seated rubber sheets which are to form the cover of the ball. This results in the formation of a complete ball having internal and external rubber spheres and an The molds of Figs. 1 and 4 can be used in presses such as shown, for instance in Patent No. 1,553,560 of James Schaefer, issued September 15, 1935; or one of the parts of the mold may. be

attached to the head of a press and the other to the movable platen thereof, as illustrated for example in my Patent 1,388,124 issued August 16, 1921. 3

After the reinforced ball with the thin rubber covering is removed from the mold member, I prefer to dust it with soapstone and wrap it tightly with cloth all over the surface,place it in a vulcanizer and give it a slight cure. This preliminary vulcanization is sumcient to prevent any slippage of the reinforcing winding.

, I now take such partially vulcanized reinforce ball and cut it in half, separate the halves and remove the forming sphere. If desired, the diametric plane for severance may be visibly indicated on the exterior of the ball by providing a slight equatorial ridge on the exterior of the forming sphere, or the valve may be marked for subsequent location by a needle stuck into it and proiecting a short distance beyond the exterior. When the ball so far formed has been cut in half, I have two sections as shown in Fig. 5, each comprising an inner lining A, one or more layers of reinforcing-material B, C, and an outside thin rubber covering designated D.

The next step in this operation is to join the two halves shown in Fig. 5. in effecting this I employ one or more intermediate rings of rubber 80 and bring the equatorial edges of the halves into pressing engagement therewith. In this operation I prefer to use two mold members shown at 85 and 85 in Fig. 6. These mold members are similar to those of Fig. 1, and have the hemispherical cavities, the annular surrounding grooves and the suction passageways already described. I seat one of the ball sections in one of the mold members, the other section in the other mold member, and I place a flat cement covered ring of raw rubber 80 across one of the exposed equatorial edges, and preferably across each of such edges, and across the surrounding vacuumgroove. I hold the sections in place in the main cavities and hold the rubber ring or rings in place by vacuum applied to the main cavities and to the suction groove. 1 now bring the two mold members of- Fig. 6 together forming a junction of the edges and the rubber ring or rings 00, thus making a complete and effective seam between the equatorial edges of the sections and at the same time pinching oif the surplus rubber. This gives me a complete effectively seamed ball with a rubber interior and a rubberexterior and an intermediate reinforcing portion composed of one of more layers of rubberized tape. r

If the ball is to be further reinforced, my next rtep isto inflate it by means of a hypodermic needle inserted through the valve 35 and give it one or more further spiral windings, as indicated in Figs. 2 and3, or the winding in various directions, as shown in the Fig. 7, where E indicates the ball produced by Joining the two sections, and F indicates the rubberized tape all:

plied to the exterior thereof. I may then apply an additional covering of rubber, if a wear-resisting cover is required. If the ball is to be used within a leather envelope, such outer rubber ,cover may be omitted. In either case an additional final vulcanizing cure in amold is effected to complete the ball.

In Figs. 8 to 10, I have illustrated the formation of a hollow hemisphere of rubber on the exterior of a male molding member with provision at the same time of an annular flange utilizable in place of the applied annular rings of Fig. 6 in the formation of the joining seam between the two'halves. Figs. 8 to 13 also illustrate the winding of the reinforcing rubberized strips on the exterior of 'the hollow hemisphere and the subsequent joining of the sections to produce a hollow ball having an inner impervious lining, a reinforcing winding, and an outer cover.- The ball thus produced corresponds to that delivered" by the apparatus of Fig. 6, and such ball is equally applicable to the external winding of Fig. 7 as heretofore described.

Referring now to Figs. 8, 9 and 10, I00 indicates a suitable standard in which is mounted a hollow spindle IOI carrying a disc I02. Rigidly secured to the face of this disc, within the conical portion thereof, is a hemispherical forming member I03 having numerous holes I04 through it. Accordingly, suction applied to the hollow spindle IOI can be utilized in seating a rubber sheet on the convex exterior of the member I03, thus forming a hollow hemisphere of rubber having an annular flange portion lying against the conical edge of the disc I02. An opening I05 in the forming member provides for seating of a rubber valve,

' as explained with reference to Fig. 1.

Figs. 8 and 9 show at I I0 an annular frame having an annular suction groove communicating with a suction nipple 2. A sheet of raw rubber shown at G is placed upon this frame and suction applied, thus attaching the sheet at the annular groove holding it stretched across the open space within the ring frame. Thereafter the frame I I0 is moved across the dome I03and over the conical flange I02, while suction is applied to the hollow spindle IOI. Then the suction is released through the passageway H2.

The action described, at first anchors the central region of the rubber sheet to the crest of the hemispherical mold member I03, as shown in Fig. 8 and then, as the frame ring moves farther across the mold member, seats the rubber sheet snugly against the entire convex exterior of the mold member and against the conical extension, as shown in Fig. 9.

When the suction is released from the carrying ring H0 and such ring withdrawn, there remains on the hemispherical mold I03 a seated sheet of rubber with aprojecting annular flange comparable to a hat with a brim, as shown in Fig. 10. While this rubber member is thus mounted-I apply power to the spinde IN, and, without releasing the suction, rotate the spindle, thus rotating the seated rubber article. While the article is rotating, I wind a strip of rubberized tape I20 into place with the edges overlapping on the hemispherical seated rubber, as shown in Fig. 10, thus reinforcing the hat shaped member H with a reinforcing layer J.

I now release the vacuum from the spindle IM and remove the hat shaped rubber article and place it in one of the mold members I30, shown in Fig. 11, place another similar article In the and each has a hemispherical cavity surrounded by a; groove with an intermediate cutting ridge,

and each has passages communicating with a nipple I32 for attachment of a suction hose.

some

When the two hat-shaped members have been seated in respective cavities and held by suction and these mold members brought into conjunction, and forced. together by the pressure of one mold member onthe other, an effective seam is formed and the excess rubber pinched on, as illustrated in Fig. 12, where the excessrubber is shown at K and the pinching annular grooves at k.

The operation just described gives me the reinforced ball of Fig.13. which ball may now, if desired, be inflated through its valve and placed in the apparatus of Fig. 3 and oneor more subsequent windings applied to the exterior, and thereafter the ball may be covered while suction withdraws the air from between the ball and cover by such apparatus as shown in Fig. 4. This produces a ball ready for vulcanization unless subsequent winding is desired, as shown for instance in Fig. 7. -Such winding may be applied before or after the cover is attached. Thereafter the ball is vulcanized either with the winding exposed or with the outer covering vulcanized to it.

It will be seen that whether I make the ball sections by the apparatus and operation indicated in Figs. 1. to 6 having the cavitary mold .or by the dome apparatus of Figs. 8 to 10, I produce two hemispherical sections of thin raw rub- 1 her reinforced by an external winding of vulcanizable tape. and I join these two sections by an equatorial seam provided by annular raw rubber and cement. The reinforcing is strong enough to, hold the thin raw rubber in shape when the parts are closed to make a hollow sphere o that the inflation will give it body enough for the subsequent winding. In each case I form a complete,

member in one of the lined molds, bringing the other lined mold into conjunction with the first mold to form a closed elastic envelope about the rigid forming member, winding an elastic envelope of tape, cutting the wound ball in two and removing the forming member, bringing the half sections together upon an interposed annular layer of vulcanizing material, and vulcanizing the product.

2. The method of making hollow rubber balls comprising seating sheet rubber stock in two cavitary molds each having a hemispherical cavity, placing a spherical rigid forming memher in one of the lined molds, bringing the other lined mold into conjunction with the flrst mold to form an elastic envelope about the rigid 8 thembyaseamandcomplctingthevulcaniaae tion oftheproduct.

3. The method of making hollow balls comprising seating sheet rubber stock by suction in two cavitary molds each having a hemispherical cavity, placing a spherical rigid forming member in one ofthe lined molds, bringing the other lined mold into conjunction with the flrst mold to form an elastic envelope about the rigid sphere, winding the elastic envelope with tape, cutting the wound ball in two and removing the sphere, providing each hemisphere with an individual annular layer, and bringing the equatorial edges of the hemispheres and the two layers into conjunc tion and uniting them to form an eifective seam.

4. The method of making hollow rubber balls comprising seating sheet rubber stock pneumatically in two cavitary molds each having a hemispherical cavity, placing a spherical rigid forming member in one of the lined molds, bringing the other lined mold into conjunction with the first mold to form a closed rubber envelope about the rigid sphere, cutting the ball in two and removing the sphere, providing each hemisphere with an individual annular layer of rubber material, brin ing the equatorial edges of the hemispheres and layers into conjunction, removing the excess rubber at the exterior of the scam, and vulcanizing the product.

5. The method of making a hollow elastic ball comprising seating sheet rubber stock by pneumatic pressure on the exterior of a convex hemispherical forming member-having an outward annular flange at the equatorial edge, such stock extending across the flange, reinforcing such seated stockby an external winding of tape,

thereafter bringing two of the reinforced sections together with the flange portions abutting and joining the same under pressure.

6. The method of malsing hollow elasticballs of rubber-like material comprising seating sheet rubber stock on the exterior of a convex hemispherical forming member having an outward annular flange at its equatorial edge-so that such stock extends across the flange, reinforcing the stock while it is thus seated by an external winding of rubberized tape wound spirally with the edges overlapping. thereafter bringing two of such reinforced members into conjunction to join their'flanges and vulcanizing the product.

'7. The method of making hollow rubber balls comprising seating sheet rubber stock on the exterior of a convex mold member having an edge flange to produce dome-shaped articles with brims, seating the body of such articles in cavitary molds and seating the brims of the same by suction applied thereto, and bringing two of such seated articles into conjunction and joining the brims and pinching oi! the surplus of stock.

8. The method of making rubber balls comprising forming by pneumatic pressure dome-shaped rubber articles with brims, seating two of such articles in a pair ,of cavitary molds with suction applied to seat the body of the article and to seat the brim about it, bringing two of such seated articles into conjunction under pressure to join the equatorial edges of the articles at the brim and pinch oil. the surplus portion of the brim, and thereafter vulcanizlng the product.

9. The method of making hollow balls comprising supporting sheet rubber stock across an open frame, the stock being retained at its edges on the frame, moving'suchframe relatively across a dome-shaped hollow member to which suction is applied to seat the stock on the exterior thereof.

9 seating two of such formed articles in cavitary molds, bringing two of such molds into conjunction and joining the two members.

10. The method of making hollow rubber balls comprising supporting sheet rubber stock across of the brims, and vulcanizing the product.

11. The method of making reinforced rubber balls comprising forming .by pneumatic pressure dome-shaped articles with brims of sheet rubber, winding rubberized tape onto the dome-shaped portion with the edges of the tape overlapping.

seating two of such wound articles in a pair of cavitary molds, bringing two of such seated articles into conjunction under pressure to join the equatorial edges of the articles at the brims, and thereafter vulcanizing the product.

12. The method of'making a hollow elastic ball comprising seating sheet rubber stock on the exterior of a convex forming member having an outward annular flange by suction through the forming member, such stock extending across the flange, thereafter bringing two of the formed sections together with the flange portions abutting and joining the same under pressure.

13. The method of making a hollow elastic ball comprising seating sheet rubber stock on the exterior of a convex hemispherical forming member by suction through the forming member, thereafter bringing two of the formed sections together and joining the same under pressure.

FRED THOMAS ROBERTS.

REFERENCES CITED The following references are of record in th file of this patent:

UNITED STATES PATENTs Number Name Date 1,387,805 Roberts Aug. 16, 1921 1,400,146 Eggers et al. Dec. 13, 192i 1,530,410 Reach Mar. 17, 1925 1,771,861 Penfold July 29, 1930 2,194,132 Voit et a1. Mar. 19, 1940 2,210,954 Roberts Aug. 13, 1940 

1. THE METHOD OF MAKING HOLLOW RUBBER BALLS COMPRISING SEATING SHEET VULCANIZABLE MATERIAL IN TWO CAVITARY MOLDS, PLACING A RIGID FORMING MEMBER IN ONE OF THE LINED MOLDS, BRINGING THE OTHER LINED MOLD INTO CONJUNCTION WITH THE FIRST MOLD TO FORM A CLOSED ELASTIC ENVELOPE ABOUT THE RIGID FORMING MEMBER, WINDING AN ELASTIC ENVELOPE OF TAPE, CUTTING THE WOUND BALL IN TWO AND REMOVING THE FORMING MEMBER, BRINGING THE HALF SECTIONS TOGETHER UPON AN INTERPOSED ANNULAR LAYER OF VULCANIZING MATERIAL, AND VULCANIZING THE PRODUCT. 